Study aim: Determination and Comparison of the Effects of a Parenteral High-Protein Diet Containing an Amino Acid Solution, Dextrose, and Soybean Oil-Based Lipid with SMOFlipid and Royal Jelly on the Composition of Intestinal Microbiota in Children with Acute Leukemia Following Hematopoietic Stem Cell Transplantation (HSCT) Design: Intervention Group 1: SMOFlipid and placebo; Intervention Group 2: SMOFlipid and royal jelly; Control Group: Intralipid and placebo. This is a controlled, double-blind, phase 3 clinical trial involving 30 patients who were randomized using block randomization. Settings and conduct: Study Location: Tehran Pediatric Medical Center Study; Population: Children with acute leukemia who are candidates for HSCT; Type of Blinding: Double-blind; Method of Blinding: Each lipid dose is completely wrapped in foil, ensuring that the type of lipid remains concealed. Royal jelly and placebo capsules are administered in identical forms, with the same taste and consistency. Participants/Inclusion and exclusion criteria: Inclusion criteria: Acute leukemia undergoing HSCT; informed consent; age over 2 and under 18 years; indication for starting parenteral nutrition. Exclusion criteria: presence of specific disease or renal/hepatic failure; allergy to peanut/soy; allergy to fish; serum triglyceride levels above 200 at the beginning of the study Intervention groups: Intervention Group 1: SMOFlipid and Placebo (intravenous lipid injection combined with oral intake of a capsule identical to royal jelly containing a placebo). Intervention Group 2: SMOFlipid and Royal Jelly (intravenous lipid injection combined with oral intake of royal jelly capsules). Control Group: Intralipid and Placebo (intravenous lipid injection combined with oral intake of a capsule identical to royal jelly containing a placebo). Main outcome variables: Fecal microbial species; Fecal microbial products (short-chain fatty acids)